Final answer:
To determine the number of water molecules in the hydrate of copper(II) sulfate, we can use the given information. We start with a 14.220 g sample of the hydrate and heat it to 300°C. After heating, the resulting anhydrous salt, CuSO4, has a mass of 8.9935 g. The difference in mass, 14.220 g - 8.9935 g = 5.2265 g, represents the mass of the water that has been driven off.
Step-by-step explanation:
To determine the number of water molecules in the hydrate of copper(II) sulfate, we can use the given information. We start with a 14.220 g sample of the hydrate and heat it to 300°C. After heating, the resulting anhydrous salt, CuSO4, has a mass of 8.9935 g. The difference in mass, 14.220 g - 8.9935 g = 5.2265 g, represents the mass of the water that has been driven off. To calculate the number of moles of water, we need to convert the mass to moles using the molar mass of water which is approximately 18 g/mol. Therefore, the number of moles of water is 5.2265 g / 18 g/mol = 0.2904 mol. Lastly, to determine the value of 'n' in the hydrate formula CuSO4 · nH2O, we consider the ratio of moles of water to moles of anhydrous salt. From the equation, 1 mole of CuSO4 corresponds to 5 moles of water, so for 0.2904 mol of water, we have 0.2904 mol / 5 = 0.0581 mol of CuSO4. Therefore, the empirical formula for the hydrate is CuSO4 · 0.0581H2O.
To find the molecular formula, we need the molar mass of the hydrate. The molar mass of the anhydrous salt CuSO4 is approximately 159.6 g/mol. From the given information, the molar mass of the hydrate is 94.1 g/mol. To find the value of 'n', we divide the molar mass of the hydrate by the molar mass of the empirical formula unit. Therefore, 94.1 g/mol / 159.6 g/mol = 0.590. Lastly, we multiply the subscripts in the empirical formula by the value of 'n'. The molecular formula for the hydrate of copper(II) sulfate is CuSO4 · 0.590H2O.